POLICE are appealing for the public's help to track down the man who knocked down and robbed a 17-year-old girl as she walked through the town centre on Monday afternoon.

POLICE are appealing for the public's help to track down the man who knocked down and robbed a 17-year-old girl as she walked through the town centre on Monday afternoon.

The attack took place just after 2pm as the girl, who is not being named, made her way along Marina Walk.

A man wearing a black motorcycle crash helmet jumped out of an alley and grabbed her New Look carrier bag which contained some cash.

A police spokesman said: 'The girl was knocked to the ground and left shocked but otherwise unhurt. The offender ran off and was seen to get on to a red and black off-road scrambler motorbike before escaping along Marina Drive.

'We are appealing for any witness who saw the robbery and, in particular, a 6ft man dressed in a pink or salmon shirt or top who chased the offender down the alley.

'We believe this witness may have been in the Halifax Building Society when he saw the robbery taking place and tried to help.'

He added: 'I would ask anyone who saw what happened or who can help us with our enquiries to come forward, especially the witness described, who may have vital evidence. This was a nasty attack which could have been worse had the young lady been hurt.'